When a QWebEngineView is on a modal dialog then a webpage with a select tag will not respond well to the mouse. It is possible to open the combobox with the options but using the mouse to select any of them will not have any effect. This works fine if the dialog is not modal or if the QWebEngineView is on a widget instead.
|For Gerrit Dashboard: QTBUG-54836|
|170888,8||Fix select tag interaction when the web view is inside a modal dialog||5.6||qt/qtwebengine||Status: MERGED||+2||0|
|174992,2||Fix RenderWidgetHostViewQtDelegate ownership for modal popup case||5.6||qt/qtwebengine||Status: ABANDONED||+1||0|